(Here is) a Parable of the Garden which the righteous are promised: in it are rivers of water incorruptible; rivers of milk of which the taste never changes; rivers of wine, a joy to those who drink; and rivers of honey pure and clear. In it there are for them all kinds of fruits; and Grace from their Lord. (Can those in such Bliss) be compared to such as shall dwell for ever in the Fire, and be given, to drink, boiling water, so that it cuts up their bowels (to pieces)?

There are many millions of people who must be cautious about consuming milk and milk by-products. For this group, there are four principle reasons for their caution:

1. Lactose Maldigestion, also known as Lactose Intolerance, or (incorrectly) as lactose allergy. The digestive system does not produce enough of the lactase enzyme to break down the complex lactose sugar into simpler sugars. The lactose sugar ferments in the small intestine, producing gas, bloating, cramps, and diarrhea.

2. Milk Allergy. This is a true allergic reaction by the body's immune system to one or more of milk's proteins, such as casein or lactoglobulin. The resulting symptoms typically include swelling, itching, bronchospasm, hives, hypotension or shock, abdominal cramps and diarrhea.

3. Casein Intolerance. This is when the immune system of the body produces IgA and IgG antibodies to casein, a milk protein. The community avoiding casein are the people afflicted with autism.

4. Villous Atrophy. This is discussed in the Medline abstracts found in the Educational Institution section below. For these people the casein milk protein causes the intestinal villi to flatten, much like it does when gluten is consumed by somebody that is intolerant to gluten.

The symptoms characteristic of lactose intolerance include bloating, flatulence, abdominal cramping, and frothy diarrhea. Lactose intolerance affects a large number of people worldwide. Lactose intolerance is more frequent among certain ethnic groups (African Americans, Native Americans, Hispanics, Asians, certain Jewish groups, and Arabs) affecting as many as 60 - 90% of older adults in those groups. The prevalence among Caucasians is about 6 - 12%.

"Condition caused by an absence of lactase: Lactose intolerance which causes cramps, bloating and diarrhea when dairy products are consumed. People who are naturally lactose intolerant: 20% of Caucasians and up to 90% of people of African and Asian descent."

It's a strange irony that the substance we depend on for nutrients early in life can trigger unpleasant symptoms when we consume it as adults. But in North America alone, lactose intolerance - the inability to digest the main sugar in milk - affects more than 30 million adults, mostly of African or Asian descent. Northern Europeans, on the other hand, tend to retain the ability to break down lactose.

Now new research, published in the February issue of the journal Nature Genetics, has finally revealed the long-sought genetic basis for lactose intolerance.

Studying the DNA of nine extended Finnish families, Leena Peltonen of the University of California, Los Angeles, and colleagues discovered two DNA variants located outside the lactase gene itself that correspond to lactose tolerance and intolerance. Importantly, lactose-intolerant members of the Finnish families shared the same DNA variant found in lactose-intolerant individuals from Germany, Italy and South Korea, among others, which suggests to the researchers that lactose intolerance has ancient roots. Indeed persistent lactase activity, they say, may have only evolved with the advent of dairy farming, around 10,000 years ago.

Allergy and Intolerance -- Different Problems
Food intolerance is a much more common problem than allergy. Here, the problem is not with the body's immune system, but, rather, with its metabolism. The body cannot adequately digest a portion of the offending food, usually because of some chemical deficiency. For example, persons who have difficulty digesting milk (lactose intolerance) often are deficient in the intestinal enzyme lactase, which is needed to digest milk sugar (lactose). The deficiency can cause cramps and diarrhea if milk is consumed. Estimates are that about 80 percent of African-Americans have lactose intolerance, as do many people of Mediterranean or Hispanic origin. It is quite different from the true allergic reaction some have to the proteins in milk. Unlike allergies, intolerances generally intensify with age.

Except for certain populations of Western humans, milk consumption stops (or is greatly reduced) with weaning. It also happens that in animals and most humans there is a decline in the level of production of lactase with aging. Lactase is the enzyme that digests milk sugar. (Curtis).

Evolution in pastoral ancestors that kept dairy animals, in populations of Europeans and some Africans, is thought to have produced the modern people who are lactose absorbers throughout adult life. There may have been a selective advantage in that group during times when milk and dairy products were relied on almost exclusively for nutrition during shortages of other foods (Houts). About 10,000 years have passed since the milking of domestic animals was begun. Nigeria is a case that demonstrates the significance of this lifestyle on human evolution. In the southern region, where conditions are not favorable for cattle, milk is not part of the diet. People there develop lactose intolerance. In contrast, a nomadic tribe that has been raising milk cattle for thousands of years remain lactose tolerant. Most African Americans are descendants of the nonpastoral tribes from Western Africa and do not tolerate lactose well. (Keeton and Gould)

In Caucasians only about 15% develop lactose intolerance while 80-90% of the African American and Asian populations are affected.

When Milk Makes You SickTherese Passerini, presented for the Evolution & the Nature of Science Institutes (NABT) November 4, 1998

Got milk? If not, then thank your lucky stars. Because if you do, medical research shows that you are likely to be plagued by anemia, migraine, bloating, gas, indigestion, asthma, prostate cancer, and a host of potentially fatal allergies -- especially if you are a person of color.

But milk is also a racial issue. Almost 90 percent of African Americans and most Latinos, Asians, and Southern Europeans lack the genes necessary to digest lactose, the primary sugar in milk. The milk industry's response is classic: they have launched new campaigns arguing that non-whites can digest milk if they take in small sips during the day. There is a burgeoning industry worth $450 million a year churning out products designed to minimize lactose intolerance.

Lactose intolerance is the most common "food allergy," but to call it an allergy is to take a white-centric view that trivializes the fact that most of the world's people are not biologically designed to digest milk.

Milk does no body good, but for the vast majority of the world's people -- people of color -- it is a public health disaster. ..........

In what they claim is the first direct evidence of the evolution of lactase-persistence (the ability to digest milk and other dairy foods), German and British researchers came up empty in their search for the gene variant that allows over 90 percent of northern Europeans to gulp down and properly digest milk. In many others around the world, lactose causes diarrhea and bloating, especially in adulthood.. . .

According to the study, the ability to process lactose was not highly prevalent in the Neolithic era. In fact, the researchers did not find any trace of the gene variant in their samples. The total absence suggests that no more than about 40 percent of the population could possibly have been lactose tolerant 5,000 years ago—indicating that the ability to digest the milk sugar probably resulted from the advent of dairy farming.

"Eight thousand years, in evolutionary terms, is nothing, especially when a genotype frequency raises from close to 0 up to more then 70 percent and, in some areas of northern Europe, [to] even more than 90 percent," Burger says, adding he expected to find that some individuals were lactase-persistent. "The fact that we have found none demonstrates that positive selection was acting massively on prehistoric European populations and that the speed of the spread of the allele (gene variant) was enormous."

All humans have the bulk of their genetic heritage in common and possess the same set of genes. But because of mutations, or changes in DNA, each gene comes in several slightly different versions, and some of them are more common in one ethnic group than another. These genetic differences often have medical significance, since some occur among genes that affect susceptibility to disease and the response to drugs.

It has long been known that some diseases are not evenly distributed. For example, a mutation that causes hemochromatosis, a disorder of iron metabolism, is rare or absent among Indians and Chinese but occurs in 7.5 percent of Swedes. A common mutation that causes sickle cell anemia is prevalent among Africans and is thought to have originated among Bantu-speakers before the Bantu expansion 2,000 years ago.

Lactose intolerance, the loss of the ability to digest lactose after weaning, is the default condition of humankind but among Northern Europeans the ability is often retained into adulthood. The reason is a mutation that may have been favored among early cattle farmers.

The following is a hadith found on many Islamic websites but no source is mentioned:

"Drink milk, for it wipes away heat from the heart as the finger wipes away sweat from the brow. Furthermore, it strengthens the back, increases the brain, augments the intelligence, renews vision, and drives away forgetfulness."

There is nothing particular in milk that science has proven to be specifically beneficial for all that is mentioned above. There are many foods which are also beneficial.

Narrated Abdullah ibn Abbas:
I was in the house of Maymunah. The Apostle of Allah (peace be upon him) accompanied by Khalid ibn al-Walid entered. Two roasted long-tailed lizards (dabb) placed on the sticks were brought to him. The Apostle of Allah (peace be upon him) spat. Khalid said: I think that you abominate it, Apostle of Allah. He said: Yes. Then the Apostle of Allah (peace be upon him) was brought milk, and he drank (it). The Apostle of Allah (peace_be_upon_him) then said: When one of you eats food, he should say: O Allah, bless us in it, and give us food (or nourishment) better than it. When he is given milk to drink he should say: O Allah! bless us in it and give us more of it, for no food or drink satisfies like milk.

Instead of finding any reliability in the Qur'anic claim that ('cattle's) milk is good for all people at all times, the findings of daily life and modern science prove exactly the opposite and are actually strongly suggestive of genetic Evolution at work.

Like most of the research cited on this page, the last article authored by Nicholas Wade for the NY Times basically states that Northern Europeans are among the rather small group of the totality of humankind to whom consumption of milk after the weaning stage is most 'agreeable' due to evolutionary changes. For much of the rest of humanity lactose-intolerance after the weaning stage is default.

So the Qur'anic statement "And verily in cattle (too) will ye find an instructive sign...We produce, for your drink, milk, pure and agreeable to those who drink it" is more appropriate to the genetic cluster of (largely non-Muslim) Northern Europeans and their US descendants than to the other genetic clusters among humanity.

This page is featured in the core article, Islam and Science which serves as a starting point for anyone wishing to learn more about this topic